Thermorubin is an antibiotic that has the same spectrum of activity as penicillin but shows no cross-resistance with penicillin-resistant organisms. Thermorubin is also "non-toxic" but its insolubility does not allow sufficiently high blood levels to be achieved. Thus, its therapeutic use is limited. We have as our objectives (a) the development of a synthetic route to thermorubin which would allow the synthesis of simpler analogs hopefully more soluble but also biologically active. Such work would also allow a chemical structure proof of thermorubin itself; (b) the development of some more soluble derivatives from the antibiotic itself through a study of its chemistry (c) the identification of thermorubin-3 and -C, lately obtained from a new fermentation and (d) the exploring of a new method for the protection of phenolic groups.